The following studies are planned as a continuation of ongoing research activities. 1. Characterization of Beta-thalassemia among Chinese through haplotyping, RNA blot hybridization analysis, oligonucleotide hybridization, and in selected cases by cloning and sequence analysis. Special emphasis is to be placed on minority races in China. 2. Characterization of two forms of HPFH (AGamma(DeltaBeta)+ and GAGamma(DeltaBeta)+) and one form of GGamma-(DeltaBeta)-thal which were recently discovered in a few families. The analyses of the GAGamma=(DeltaBeta)+-HPFH is particularly important for our understanding of the Gamma yield Beta switch. 3. Numerous babies have been observed with variations in the relative quantities of the GGamma and AGamma chains of their Hb F. Some of thes are due to Gamma globin gene deletions. It is intended to restudy these babies using existing DNA methodology to evaluate possible morbidity of the Gamma-thalassemia. 4. The Alpha-thalassemias of mainly South Chinese families will be studied with established procedures. However, the non-deletion type of Alpha-thal-2, seen mainly in one region, will be studied by oligonucleotide hybridization and by gene mapping to evaluate the possible presence of the unstable Hb Quong Sze which causes Alpha chain deficiency. 5. Prenatal diagnosis for the deletion types of Alpha-thalassemia will continue using methods developed in our laboratory, while that for Beta-thalassemia will be initiated based on haplotyping methodology, oligonucleotide hybridization, and, if possible, gene mapping. 6. Analyses of abnormal hemoglobins will continue but will be limited mainly to pathological variants.